The disclosure generally relates to a desalination technology, and more particularly to super-capacitor desalination (SCD) devices and methods.
One conventional SCD device generally has a pair of terminal electrodes supplied with opposite polarities for generating an electric field therebetween. A chamber between the terminal electrodes allows a feed stream to be treated to pass through. One or more bipolar electrodes may also be employed between the terminal electrodes for forming more chambers to multiple feed streams.
The conventional SCD device is periodically operated in a charge mode and a discharge mode due to the capacity limitation. In the charge mode, the chambers function as dilute chambers where ions in the feed streams are absorbed onto the electrodes under the electric field to produce dilute solution. When the capacity of the electrodes (terminal electrodes or the bipolar electrodes) is full or nearly full, the conventional SCD device is switched into the discharge mode by shorting the terminal electrodes. Accordingly, the dilute chambers are changed into concentrated chambers where ions in the electrodes enter into the feed streams to produce concentrated solution. With such configuration and operation mode, neither the dilute solution nor the concentrated solution can be produced continuously.
Further, another conventional SCD device additionally employs an energy recovery (ER) device to gather energy generated at the discharge mode. The gathered energy is reused by another SCD device in the charge mode, which decreases overall power consumption but causes higher production cost due to the extra ER device. Furthermore, the ER device consumes some gathered energy due to its own resistance.
Therefore, there is a need to provide improved SCD devices and methods that can provide product water in a continuous way. Further, there is another need to provide SCD devices that can gather energy generated in the discharge mode without an ER device.